docstr: Returns if the xpos tags are part of a composite vocab
docstr_tok: ["Returns","if","the","xpos","tags","are","part","of","a","composite","vocab"]
code: def is_composite_xpos(self):
      """
      Returns if the xpos tags are part of a composite vocab
      """
      return isinstance(self.vocab["xpos"], CompositeVocab)
  
file_path: stanza/stanza/pipeline/pos_processor.py
imports: import torch
  from stanza.models.common import doc
  from stanza.models.common.utils import unsort
  from stanza.models.common.vocab import VOCAB_PREFIX, CompositeVocab
  from stanza.models.pos.data import Dataset
  from stanza.models.pos.trainer import Trainer
  from stanza.pipeline._constants import *
  from stanza.pipeline.processor import UDProcessor, register_processor
  from stanza.utils.get_tqdm import get_tqdm
label_desc: Use image node_id 4 for calling the POSProcessor obj's underlying member method code with example usage: obj.is_composite_xpos() and returns: isinstance